Poly(haloethyl-ethyleneoxy) phosphoric acid ester polymers

ABSTRACT

Liquid poly(haloethyl-ethyleneoxy) phosphoric acid esters are prepared by condensing tris (2-haloethyl) phosphate at a temperature of from 140* to 220*C. in the presence of a catalyst until from about 0.5 to about 0.9 moles of ethylene dihalide per mole of tris(2-haloethyl) phosphate is evolved. A low acidity product is obtained. Any residual acidity in the product is substantially eliminated by neutralization with an alkylene oxide.

[ U UN Filed:

mun HAkOETfiI'L-F-TMYLENEOXY WEOSPRQQIC ACE.) m POLYMERS inventor: 45m D. View,

Madame-Hudson. N.Y.

Aaignee: Smfler Chemical Conway. Weatpon. Conn.

Oct. 25. 1973 Appl. No; 409.486

Related U.S. Apfiicallol Data Contlnusticm-in-pnrt of Ser. No. 164.928. July 2]. "WI. abandoned. which is n continuation of Set. No. 760.988. Sept. I). 1968. abandoned.

US. Cl. 260/923; l06/l5 FP; 260/15 A];

260145.? P; 260/97]; 260/982 Int. Cl C071 9/68 Field of Search 260/928. 982

Reference: Cited UNITED STATES PATENTS 5/1912 Wu zoo/9s: x

in: FOR MlSSlNG XR SEARCH RQP-M lHl 3.8%,w7 1 July 22, I975 FORE-JON PATENTS OR APPLlCATlONS 1.202.50l I0ll965 Gummy 260/982 OTHER PUBLICATIONS Konhak. Chemical Abstract: 52 I958) l2804.

Primary Examiner-Anton H. Sutto Amman! Examiner-Richard L. Raymond ABSTRACT 2 Clubs. N0 Dramlegs E Mun WSEEDEW) more new no can CRWREFERENJE TO RELATED APPLWZA'HQNS The present invention is a continuation-Qu nn application ofSer. No. "H.928. filed July 2|. I97! and now mite-phosphorus polymers and to their method of preparation from tris( Z-haloethyl) phosphates. The products of the invention which can be termed poly nlocthyl-ethyl-eneoxy) phosphoric acid esters are tlarne retardant agents particularly for use in polyurethane compositions and ceiiulose acetate films.

Tris(2-hal)ethyl) phosphates and particularly trislZ- chloroethyl) phosphate are known compounds. the chloro derivative being a known flame retardant agent for polyurethane foams. It is also known in the prior art that the chloro compound will undergo polycondcnsa' tion with the splitting out of ethylene dichloride to form solid polymers. These solid polymers are prepared. in accordance with the procedure of German patent No. l.202.50l. by heating tris( Z-chloroethyl) phosphate at temperature within the range of I90 to about 240C. in the presence of a basic catalyst until about one mole of ethylene dichloride per mole of trist 2-chloroethyl) phosphate is generated.

Liquid polycondcnsed polymers of trin(2- chlorocthyl) phosphate have also been prepared by heating the phcmphate to temperatures within the range of from 246 to 230T. (Korshalt ct al. Bull. Acad. Sci.

USSR. Chem. Section. "258. pp. lQb-Zfll 'lnis reac' tiun at this temperature is complex and uncontrollable. The products are dark. viscous. fluids which are highly acidic. The acidity makes the products undesirable for use as flame retardant agents for polyurethane prepared by normal procedures using the monomer amine catalyst system in that the high acidity tends to neutralize the catalyst. and their color reduces their usefulness ss flame retardants for most plastics.

it has now been found that liquid polycondensation products of trist Z-hnloethyl) phosphate and. particularly tristZ-chlorocthyl) pl'mphate can be easily prepared by a carefully controlled polycondensation reac' tion to yield substantially clear. colorless polymeric products which are useful as Home retardant additives. particularly for polyurethane foams.

in accordance with the present invention. liquid poly(hnloethyl-ethyleneoxy) PllOfiPl'iOflC acid esters are provided by heating a Z-haloethyl phosphorus compound resction mixture containing a major proport'wn (at least 50%) of trist Z-lialoethyl) phosphate and is minor proportion of other esters oi phosphorus having at least one Z-hstloethyl subrt'rtuent to e temperature within the range of from about I40 to shout 2001. in the presence of a basic catalyst for a period of time ruti'icicnt to generate reaction byproduct ethylene dihelide in an amount of from about 0.5 mole to about 0.9 mole per mole of Z-haloethyl phosphorus compound. The products are clear liquids and can have varying degrees of polymerization and viscozity depending on the amount of ethylene dihalid-r generated durhg the polycondensation reaction which can be controlled by edjustm nt ol reaction conditions. The products are cs- 2 tremely km in acid content though any residual acid content can be substantially eliminated by post treating the reaction product with an acidity neutralizing agent such as an ethylene oxide at s temperature ranging from smtn'ent to the polymerization temperature. The

products can be effectively used as flame retardant ndditives for polyurethane foam. Particularly. the products of the present invention can unexpectedly provide llarne retardant properties using smaller amounts and correspondingly at lower phosphorus and chlorine levels than that required to provide similar llume retardant properties using tris(2-haloethyl) phosphate alone. This is surprising inasmuch as the quantity of phosphoms and chlorine in the sdditive is generally determinalive of the effectiveness of the additives as a flame retardent.

TrisQhaloethyI) phosphates are a known class of compounds which can be easily prepared by known methods. These compounds are preferably the chloro or isrorno derivatives. The term tris( l'haloethyl) phosphate is also intended to include mixed halo derivatives -and also mixtures of derivatives as well as pure tris phosphate.

The triefllhaloethyl) phosphate constitutes the major proportion of the reaction mixture used in the polyeondcnsation reaction of the present invention. Preferably. the reaction mixture is constituted solely of the triQ-hnloethyl) phosphate compound though the reaction mixture can also contain a minor proportion, i.e.. from 0 to about 50% by weight of another ester of phosphoric acid having at least one Z-lmloethyl substitucnt thereon. A: with the "is eaten. the l'chloroethyl derivative is preferred. The remaining ester group can be any organic radicals which do not interfere with the polycondcnsntion reaction and these can be illustrated by lower allay-l groups of from I to it) carbon atoms. nryl. such as phcnyl; substituted alisyl. arylalkyls. e.g.. benzyl and ar-methylbenzyl'. substituted aryls. such as alltnryl. e.g.. tolyl. syienyl. ieopropylphenyl tbutylphenyl and chlorophenyl; hzloalityls. such as chlm roisopropyl. dichloroisopropyl. brornoehloroisopropyl. and 2.3-dibronwpropyl; and the like. Time are given as illustrative and are in no way intended to be inclusive 0! all such compounds.

The polycondensstion reaction is conducted in the presence of a basic catalyst Suitable bases include rilltali metal and alkaline earth metals. such as sodium. potassium. magnesium. calcium and the like; their osid-es. such as sodium osfie. potassium oxide. meanesium oxide. calcium oxide. and the like; hydroxides. such in sodium hydroxide. potassium hydroxide. msgnesiurn hydroxide. calcium hydroxide and the like; carbonate and bicarbonntes. such as sodium carbonate and bicm'homrte potassium carbonate and bicarbonate. magnesium carbonate and bicarbonate. calcium carbonzte and bicarbonate and the lilac; elltosides. such as sodium ethoxide. mteasium ethoxide. mgneeiurn ethoxide. cnkiuni ethoxide. and the like; plzenolates. such a sodium phenol-ate. pota-rsium phenolste. msgnesiurn ph-enoiattc. calcium phenolate. and the like. sad

salts of strong; braces and wee: acids such its alkali metal and alkali earth metal acetates. and phosphates. end salts of organic plmcphorus ncids end partial phoephste esters. Organic bores such as amines. for example. pyridine. quinoline. triethylamine. tetrsmethylgusnidiae.

3 "Whitman-hol ow. htscytzraine. mitinc. and at. like my ha used. The defmLaim or time: in the eontcxt of the want invention cttrt'td! to than: sutmtanec: known a Levin harm. that in. electron poi: donors. and that mmodest. for example. triolkylphmphines. tripienyl phorpldnes. tritrutyltin oxide and the like. The true catalyst is believed to be the union of a salt ol illhaloethyl) Phmpbtte prepared in situ by the cleavage of trist Z-halocthyll phosphate with a salt whose anion is sufficiently nucleophilic to effect the cleavage. Thus. substances not normally cumidcrcd burn such or alkali metal halide. e.5-. sodium chloride. sodium bromide. and the like. potaszium chloride. p0- talsiutn bromide. and the like. are included within the term basic catalyst as used herein inasmuch as they arc sufficiently nuclcophilic to effect the desired cleavage. Suitable quantities of base for catalyst purposes are from I few parts per million. (up. 50 p.p.m. up to about lOb by weight. preferably 0.0l-$% by weight. hascd on the weight of the reaction mixture.

The base catalyst can be liquid or solid. as desired. Suitable solid basic compounds are alkali and alkaline earth metals and their salts. such at sodium or potassium hydroxide. sodium or potassium carbonate or bicarbonate. sodium alcoholatc. and finely divided rnctallic sodium or potassium. The addition of the solid buic compound or alkali metal is accomplished by stirring the trittZ-halocthyl) phosphate with solid sodium or potassium hydroxide as pellets or flakes or with coarsely pulverized alkali carbonate or finely divided metallic sodium or potassium at room temperature 0.0l-5'lb by weight of solid basic compound or alltali metal. calculated on the trial Z-hulocthyl) phoaphate. it stirred in. The amount of solid basic compound or alkali metal thus dissolved can be determined by simple titration.

The reaction mixture is then heated to a temperature within the range of from about 140 to about 200C. arid preferably from about l70 to about 220C. for a period of time sufficient to gcncrzitc' lay-product ethylene dihalide inan amount of from about 0.5 mole to about 0.9 mole ethylene dihalidc per mole of 2- halocthyl phosphorus compound. The heating can be conducted in any type of appropriatercaction vessel. preferably a reaction vessel having a distillation apparatus attached thereto. The amount of ethylene dihah idc formed during the polyconclcnsation reaction can be easily determined by stripping the byproduct ethylene dihalide as it is formed during the reaction and dctcrmining the amount obtained until such time a: the desired reaction end point is reached. at which point the reaction can be terminated.

The amount of ethylene dihalidc formed during thc polycondensation reaction is an indication of the dcgrce of condensation. Alter generation of approximately 0.5 mole ethylene dihalide per mole of 2- luloethyl phosphorus compound, a product having an average molecular structure of the dicondensation product i: obtained. After approximately 0.9 mole ethylene dihalide has been liberated. or generated within the reaction mixture. the product has an average degree of condensation of approximatcly it). By controlling the amunt of ethylene dihulidc generated within the range of from about 0.5 mole to about 0.9 mole pcr mole of Z-halocthyl compound products of various viscotitiea having relative degrees of polymerization of ll'otn approximately 2 to about l0 can be prepared. For

3.896Jll7 @21 Ill a thaprcficrrw wduct. i.c.. the polycondcnntc 0t trizll'cltlorocthq'll plrmpltutc. the reaction is conducted until ethylene dichloride in amounts oi from about l7.5 toahout Illlrhy weight hracd on the total weight or thc reaction mixture is evolved. This corresponds to the 0.5 to 0.9 mole ethylene dichloride per mole of tristl'chloroethyl) phosphate used to prepare the product.

The products of the invention are characterized by low acid numhcrs though any residual acid content can be substantially eliminated by port treating the reaction product with an acidity neutralizing agent such as an alltylcne oxide. Any alkylene oxide can be used. Alltylene oxide is broadly intended to include any compound having an oxirane group Illustrative of these compounds are ethylene oxide. propylene oxide. butylenc oxide. styrene oxide. epichlorohydrin, epibromohydrin. diglycidyl ether. glycidyl butyl other. glycidyl alkyl ether. glycidyl ether or phenol. diglycidyl ether of rewrcinol. glycidyl ether of cresoland brominated cresol. glycidyl ester: of acids such as acetic. acrylic and methecrylic acid. glycidol. diglycidyl ethers of bisphenol A and related epoxy resins made from b'rsphcnol. or tctrahalobisphenols and cpichloroltydrin. diepoxide dicyclopentylenc ether. the diepoxide of vinylcyclohcxenc. the diepoitide 0t cyclohcxenylmethyl cyclohcxanecarboxylate. diepoxide of bis(cyclohcxenylmethyl) adipate. and the like. The alkylene oxide is used in an amount tufi'tcient to neu- 5 tralize acidity. gencrally from about 0.05 to about 5% by weight based on the total wcight ot' the product. When a gaseous cpoxidc. zuch as ethylene oxide. is cmploycd. it may conveniently be passed in and through the reaction product until neutralization is achieved. Ric unrcacted exceu which passes through can. if desired. be collected and recycled. Neutralization can be accomplished at any temperature from ambient to the polycondcmation temperature. i.c.. about 20' to shout The following examples illustrate the process of the present invention.

EXAMPLE I Vacuum stripping at IOOT. removes another 12 grams a of ethylene dichloride totalling 89 grams (0.9 mole) or approximately 20.8% (0.6 mole ethylene dichloride per mole of trial 2-chlorocthyl) phosphate). The product it a nearly colorless liquid. having an acid content of 0. l 8

w millicquivulcnts per gram (titration to Congo Red end point). By heating the product at l00C. with 5 gram. of epichlorohydrin. this acidity is eliminated.

EXAMPLE 2 no procedure of Example I to repeated with en es- 5 per gram. Treatment with 3 mm of epiehlorohyclrin at IOOC. reduce: this acidity. The acidity can be tuhstantially eliminated by addin; 8 [rumor the diepoxide of cyclohexenylmethyl eymiltiequlvelent of acid tiom may require amounts outside this range and this range is given only at a zpecific illuttrntion of the manner in which the present invention can be utilized.

The production of urethane or isocyanate polymert clolu' be carboxylete to the product and allowing the 5 is a well known commercial proceu. see for instance product to stand at 2$'-30C. for day. Kirk-Othmcr. The Encyclopedia of Chemical Technology. Fint Supplement. page: 888 et :meq. (lnterscicncc EXAMPLE 3 I957). Briefly. this process involves the reaction of an The procedure of Enmpk I is rcpeamd an ex" isocyanatc and a recond compound which may contain Mien of the beating me um approximamly 10 an hydroityl. arnino or carboxy group. t.c.. acompound hykm: dkhbddc b libflatci The produc B a highly containing active hydrogen. A preferred group of commom "quid which a! on tum," healing pounds containing active hydrogen are the dior polyfunctional hydroxy compounds. A: used in this specification the term "isocyanate material" is intended to in- EXAMPLE elude isocyanate or urethane composition! containing Mixtures of 856.4 gram: (3 mole) of tris(2- un e radicabehloroethyl) hosphate were heated to 150, I60. and Th m st mmon polymers are formed by the reac- I'IO'C. in the pretence of 0.97 grams ofaodiurn carbontion of toluene diisocyanate (herafter TDl) and a natuitte catalytt. The ethylene dichloride given off in the rerated polyester. (This latter compound may. however. action and from vacuum stripping the final product contain benzene unsaturation.) Repretentative polyev were collected. The following rcrulu were obtained: ten are the reaction producu of adipic acid and/or TABLE i SAMPLE NO I 2 4 t Trkt Z-chloroelh I) 3 .1 3 J t Phmphate (CFl (Mole!) I Reaction Temperature ('C.) I50 I50 INJ I70 I70 ieuction Time (hour!) 3| 34 6.5 9.!

' gram: "9.! l9$.6 21." v6 I501 200 2 Ethylene tmum eiolvnd Motel/mole (CEF) .64 .66 .61 .03 en Product Viscoeit) 910 3.310 441 ,Jmo

(Cpu. ZSC.)

Acid Number! tip-Acetone. 20 min I90 Ill l 2M :t o )3 I McOH-Acetone. 20 min. 3.7 I] 4 4,7 2 I l0 0 Dun-unadulter-mmr-uunut erbdrotionm caeolutunamgneunlmnhaxua Maw-nemliu tn-qknt per gnu- (tltutaon to methyl and and port-tn The product. were neutralized by bubbling ethylene oxide with ttirring into and through the renction mixture it 90'-l00C.. until I mtizi'nctorily low ac.J number (i.e.. practical neutrality) was achieved. The following viscoeity and acidity tending: were obtained:

pltthalic nnhydride and ethylene glycol. For purpoeee of rimplicity in the following rpeeification end claiml. thiz type of polyester will be identified eimply by the term phthnlic-ufipic acid type polyester": Other compounds which may be m in place of the polyesters The product! 0! the prenent invention are clear liquid: which are low in acid values which products In: extremely mm m flame retardant agents for polyurethan: forums. The compound: can be used lion: or in varloul admixture: with other known l'leme retardant agents preeently in me in the production oi flame retirttmt polyurethnne forms. The exact amount of the compounds to he need depend: on the foam density. compoeition and degree of fleme retarding required in the polyurethane foam. An effective amount for generel put-pores has been found to be within the range of (ram about 2 to about by Weight. Specific appliaare polyethen. limple gjycols. polyglycolt. enetor oil. drying oils. etc. Whether the products on to be flexible or rigid depends upon the degree of crotolinking end thus the type of polyol which ii ueed. Since the prodnets of th'u invention may reptzee only a out of the polyol. they are thus suitable for use in either flexible or rigid foam. q,

when an expanded or foemed product in to be pr! duced. it is the genernl practice to add water to the compoeition. The water react: with the --NCO group to releue CO, md cause the expansion of the polymer into a l'oemod M.

t'fontrol of this. reaction requires cunmidcrablc skill and often special e uipment. in some cases it has een found advice-hie In use inert dissolved gasses including the various halohytlrocarhons such as the ell known Freens or Gcnctrons These low boiling liquids boil when warmed by the heat of reaction and thus cause foaming. They also serve to lower the thermal conductivity and increase the flame resistance of the resulting foam. The term foaming agent" as used herein is intended to include both reactive rnls such as water and inert materials such as halohydrocarbons which cause the reaction products to form an expanded foam.

In addition to the actual reactants and foaming agents it is also desirable in many cases to add a small amount of a surfactant in order to provide a more homogeneous mixture.

The following examples illustrate the use of our new compounds in forming flame resistant polyurethane foamed products.

EXAMPLE A polyurethane foam was prepared utilizing the following composition: "a

Grams I00 30(1) M.W Iriol. product of oxypropylution of lycerol (Dow Vorun'ol CP 3000) 48.9 tmuenc dmocyunatc [80% 2.4 isomer. 2.6) It) product of Esumpk 2 L3 silicone surfactant (L-SZU Union Carbide) 3.) water ".50 dimethylethanolaminc 0.20 trimethylumimsethylpiperaline 0 70 50% solution in dioctyl phthalute of stunnous These ingredients yielded a flexible foam having a density of 2.0l lb/cu. ft. The foam was of good appearuncc. resiliency and cell size. The foam was selfextinguishing by ASTM test method D4692. A similar foam prepared using 14 parts of tris(2-chloroethyl) phosphate which provides more phosphorus and more chlorine than the l0 grams of the product of Example 2. did not provide a foam with self-extinguishing properties. This is surprising inasmuch as fire rctardance is generally dependent on the amount of phosphorus and chlorine added. Thus. only small amounts of the product of the invention are required to obtain desirable results, thereby avoiding urethane foam compounding problems generally encountered in using larger additive quantities.

It has also been found that the polycondensed prodnet is a much more effective flame retardant agent than tris(2-chloroethyl-phosphate) when used in cellulose aceifle. The amount utilized is dependent on composition, film thickness and degree of flame retardnncydesired. Effective amounts can he easily determined by one skilled in the an. no is illustrated in u followln example EXAMPLE 6 invention using the (2-chlorocthy!) phosphorus cornpound. With equal facility. (Z-bromoethyl) phosphorus compounds can also be used therein.

It has also been found that the products of the present invention are not soluble in the normal dry cleaning fluids such as perchloroethylene. whereas tristZ- chloroethyl) phosphate is highly soluble. The polycondcnsed product of Jic present invention can therefore be coated onto various fabrics, such as cotton. to give fire retardant characteristics thereto. and also. the product can be incorporated into fiber forming compositions such as acetate rayon materials. ln each case. the flame retardant agent would not be extractable by normal dry cleaning procedures. The products of the invention can also be used as additivesjo numerous polymer systems other thanthose mentioned hercinbefore as flame retardants and/or plasticizers such as to phcnolics. acrylics. polystyrene. vinyl resins such as polyvinyl alcohol or polyvinyl chloride. polyesters. polyolefins. rubber. nitrocellulose. epoxy resins and the like. The compounds can also be used in paper and fabric coatings. and in asphalt. and in adhesives as flame retardant additives.

The invention is defined in the claims which follow.

What is claimed is:

1. Liquid polytchloroethylethylencoxy) phosphoric acid esters which are prepared by reacting tris(2- chloroethyl) phosphate by ltnpting mid phosphate to a temperature within the ranig of from about M0 to about 220C. in the presence of a basic catalyst with ethylene dichloride as reaction byproduct; and terminating said reaction at a reaction byproduct level of ethylene dichloride in an amount of from about 0.5 moi: to about 0.9 mole ethylene dichloride per mole of tris(2-chlorozthyl) phosphate in said reaction.

2. The product of claim l which further includes the step of post treating the reaction product with an slltylcne oxide to neutralize the acidity in said product.

Q Q Q I O 

1. LIQUID POLY(CHLOROETHYLETHYLENEOXY) PHOSPHORIC ACID ESTERS WHICH ARE PEPARED BY REACTING TRIS(2-CHLROOETHYL) PHOSPHATE BY HEATING SAID PHOSPHATE TO A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 140* TO ABOUT 220*C. IN THE PRESENCE OF A BASIC CATALYST WITH ETHYLENE DICHLORIDE AS REACTION BYPRODUCT, AND TERMINATING SAID REACTION AT A REACTION BYPRODUCT LEVEL OF ETHYLENE DICHLORIDE IN AN AMOUNT OF FROM ABOUT 0.5 MOLE TO ABOUT 0.9 MOLE ETHYLENE DICHLORIDE PER MOLE OF TRIS(2CHLOROETHYL) PHOSPHATE IN SAID REACTION.
 2. THE PRODUCT OF CLAIM I WHICH FURTHER INCLUDES THE STEP OF POST TREATING THE REACTION PRODUCT WITH AN ALKYLENE OXIDE TO NEUTRILIZE THE ACIDITY IN SAID PRODUCT. 